Determination of Iodine Value by Dr Vimarsha Bhatkalkar.pptx

Iodine value is also called as iodine number, iodine absorption value or iodine index.

It is used in the estimation of the degree of unsaturation in fatty acids.

It is expressed in terms of the number of centigrams of iodine absorbed per gram of sample.

The double bonds present in unsaturated fatty acids react with the iodine.

The more the iodine number, the more the number of carbon double bonds that is the more unsaturated fatty acids bonds are present.

1. Dr. Vimarsha Bhatkalkar 2 nd Year PG Scholar Department of Rasashastra and Bhaishajya Kalpana KLE Shri BMK Ayurveda Mahavidyalaya and Research Centre, Belagavi, Karnataka ANALYSIS SEMINAR IODINE VALUE

2. CONTENTS INTRODUCTION OBJECTIVES HISTORY DEFINITION PRINCIPLE TYPES OF METHOD EQUIPMENTS AND REAGENTS PROCEDURE PRECAUTIONS APPLICATIONS LIMITATIONS DISCUSSION RESEARCH ARTICLES SUMMARY CONCLUSION 21-08-2024 Iodine value 2

3. INTRODUCTION WHAT IS IODINE VALUE? Iodine value is also called as iodine number, iodine absorption value or iodine index. It is used in the estimation of the degree of unsaturation in fatty acids. It is expressed in terms of the number of centigrams of iodine absorbed per gram of sample. The double bonds present in unsaturated fatty acids react with the iodine. The more the iodine number, the more the number of carbon double bonds that is the more unsaturated fatty acids bonds are present. 21-08-2024 Iodine value 3

4. AIMS AND OBJECTIVES Determination of iodine value. Importance of iodine value in ayurveda. 21-08-2024 Iodine value 4

5. HISTORY Hübl's Method (1884): The iodine value method was first introduced by the Austrian chemist Hans Hübl in 1884. In his work, Hübl used an alcoholic iodine solution in presence of HgCl2 (mercuric chloride) with chloroform as fat solubilizer to affect the addition to the double bond, followed by titration with sodium thiosulfate to determine residual iodine. Starch was used as indicator. Hübl himself already used the term  Jodzahl  (iodine number). In his work, Hübl investigated a variety of fats and oils and noted that drying oils generally tend to have the greatest iodine value and solid fats the lowest iodine values.  Wijs Method (1903) : In 1903, the Dutch chemist J. J. Alexander Wijs modified Hübl's method to improve its accuracy and reproducibility. Wijs ' method involved using iodine monochloride ( ICl ) in glacial acetic acid instead of iodine and mercuric chloride. This modification made the iodine value determination more precise and easier to perform. 21-08-2024 Iodine value 5

6. DEFINITION T he iodine value is the mass of iodine in grams that is consumed by 100 grams of a chemical substance. Iodine numbers are used to determine the amount of unsaturation in fatty acids. This unsaturation is in the form of double bonds which react with iodine compounds. 21-08-2024 Iodine value 6

7. PRINCIPLE 21-08-2024 Iodine value 7 Reaction: Iodine reacts with the double bonds in unsaturated fatty acids. Saturated fatty acids do not react because they do not have double bonds. 2. Reagents: Iodine monochloride is used to react with the oil or fat. The reaction is carried out in the dark to prevent decomposition of the reagents. 3. Excess iodine: After this reaction, there might be excess iodine monochloride that has not reacted with the oil. Addition of Potassium Idiode : Potassium Iodide is then added to the reaction mixture. It reacts with the excess iodine monochloride to release iodine.

8. CONTD… 21-08-2024 Iodine value 8 4. Titration : The released iodine is then titrated with a standard solution of Sodium Thiosulfate. Starch is used as an indicator to detect the endpoint of the titration. What is role of Sodium Thiosulfate? Sodium Thiosulfate reacts with the leftover iodine, converting it into iodide which is a different form of iodine that does not have the same color. As the iodine is converted, its color fades or disappears. 5. Determination : The amount of iodine released (from the reaction of potassium iodide) allows for the calculation of the iodine value which indicates the degree of unsaturation of the oil or fat. If the iodine number is between 0-70, it will be a fat and if the value exceeds 70 then it is an oil.

9. EQUIPMENTS 21-08-2024 Iodine value 9 Iodine flask Analytical balance Glass stopper Volumetric burette Graduated cylinder Stirrer

10. REAGENTS AND SOLUTIONS 21-08-2024 Iodine value 10 Iodine monochloride – Wji’s reagent Potassium Iodide solution Sodium Thiosulphate solution, 0.1 N – standard Starch solution, 1% - indicator Iodine monobromide – hanus method Pyridine bromide – pyridine bromide method

11. METHODS 21-08-2024 Iodine value 11 Wijs method (iodine monochloride method) Hanus method (iodine monobromide method) Pyridine Bromide Method

12. PROCEDURE 21-08-2024 Iodine value 12 WJIS METHOD Keep all the reagents solutions ready. Pipette out 22gms of fat sample dissolved in 10 ml chloroform in the iodine flask and label it as “TEST” Now add 20ml of sodium monochloride reagent ( Wjis reagent) in the flask. Mix the contents thoroughly. This flask is allowed to stand for half and hour in the dark. Now in another iodine flask, add 10ml of chloroform and label it is as “BLANK” . Add 20ml of sodium monochloride reagent ( Wjis reagent) in the flask. Mix the contents thoroughly. Incubate the flask “BLANK” in the dark for half and hour in the dark.

13. CONTD…. 21-08-2024 Iodine value 13 Meanwhile take the “TEST” sample from incubation after 30 minutes and add 15ml of potassium iodide solution into the flask. rinse the stopper and the sides of the flask using 100ml distilled water. Titrate the “TEST” sample against standardized sodium thiosulfate solution until a pale yellow/straw colour is observed. Add 1ml of starch indicator into the flask and observe for the appearance of dark purple color. Continue the titration until the color of the solution turns colourless . Record the end point of the titration. Similarly repeat the procedure for the “BLANK” sample and record the reading.

14. CONTD…. 21-08-2024 Iodine value 14 Calculation: Iodine value = (blank titer – sample titer in ml) (1.269) weight of the sample given in gram

15. CONTD…. 21-08-2024 Iodine value 15 HANUS METHOD Sample is taken in the iodine flask and rinsed with glacial acetic acid and 15 ml chloroform and is dissolved. Add iodine monobromide solution, insert the stopper. Allow it to stand in the dark for around 30 minutes. Further steps are the same as that of Wijs method. Record and calculate the iodine value.

16. CONTD…. 21-08-2024 Iodine value 16 PYRIDINE BROMIDE METHOD In this method, weighed sample is added with 10ml of carbon tetrachloride. Add 25ml of pyridine bromide solution and allow it to stand for around 30 minutes in the dark. Further procedure is same as that of Wijs method. Record the reading and calculate the iodine value.

17. PRECAUTIONS 21-08-2024 Iodine value 17 Maintain hygiene. Equipment should be clean and dry. Handle the glassware's carefully Iodine and chloroform are hazardous. Hence one must handle them with care in a well-ventilated area. Avoid inhaling fumes from chemicals like carbon tetrachloride or chloroform, which are toxic. Use gloves while handling the reagents as Iodine and other reagents can be harmful to the skin. Iodine solutions are sensitive to light. Prepare and store them in dark bottles to prevent decomposition. Readings should be noted appropriately.

18. APPLIED ASPECTS 21-08-2024 Iodine value 18 In pharmaceuticals and cosmetics, oils and fats with appropriate iodine values are selected to ensure product stability and to prevent oxidative degradation. A higher iodine value indicates a higher degree of unsaturation , which can be used to differentiate between various types of oils and fats. Oils with a high iodine value are more prone to oxidation and rancidity , affecting shelf life. Monitoring the iodine value helps in ensuring product stability and quality.

19. APPLICATIONS 21-08-2024 Iodine value 19 Cosmetics and Pharmaceuticals The iodine value helps in selecting oils and fats for skincare products like creams, lotions, and balms. The degree of unsaturation affects the texture, absorption, and stability of the products. In pharmaceutical applications, the iodine value is used to select ingredients that are stable and less prone to oxidation. This is particularly important for products that have a long shelf life. Soap Manufacturing Fats with high iodine value make softer soaps and fats with low iodine value make harder soaps. Food Industry The semi- drying oils like soybean oil contain intermediate iodine numbers while the non drying oils like olive oil which are used in food products have low iodine numbers.

20. 21-08-2024 Iodine value 20 Oils with higher iodine values are more susceptible to oxidation and rancidity. The iodine value is used to predict the shelf life of oils and fats and to ensure product stability during storage and distribution. Research and Development The iodine value is a key measurement used in research to study fats and oils. It helps the researcher to understand how the chemical makeup of these substances relates to their physical properties, like texture or stability. In research and development, the iodine value is used to create new products, such as foods, cosmetics, or industrial materials. By knowing the iodine value, the researcher can design products with specific qualities, like being more stable or having a better texture. CONTD….

21. IODINE VALUE 21-08-2024 Iodine value 21 OIL IODINE VALUE Tila taila 103-116 Sarshapa taila 98-110 Eranda taila 82-90 Sunflower oil 125-140 Palm oil 4-22 Groundnut oil 80-100 Coconut Oil 6-10 Olive Oil 75-94 Ghee 26-38 Butter 26-40

22. IODINE VALUE ACCORDING TO API 21-08-2024 Iodine value 22 TAILA IODINE VALUE Ksheerabala taila 75-100 Dhanwantara taila 100-120 Balaguduchyadi taila 80-100 Gandharvahastadi taila 75-100 GHRITA IODINE VALUE Triphala ghrita 35-45 Phala ghrita 40-53 Panchatikta ghrita 30-40

23. LIMITATIONS 21-08-2024 Iodine value 23 Determination of iodine value is only limited to fats and oils. Determination of iodine value can be time-consuming. A change in iodine value might indicate adulteration but does not specify the specific adulterant.

24. DISCUSSION 21-08-2024 Iodine value 24 Iodine value is a qualitative test for fats and oils. Wijs reagent helps in halogenation of iodine with the sample. (that is it reacts with double bonds in fatty acids present in the sample). Sodium thiosulphate and potassium iodide react with liberated iodine. Starch acts as an indicator. The iodine number is known at the end of the Wijs method (after the completion of titration step), and then calculation is performed.

25. RESEARCH ARTICLES 21-08-2024 Iodine value 25

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28. SUMMARY 21-08-2024 Iodine value 28 Iodine value is used to measure the degree of unsaturation of fats and oils. There are three methods to determine the iodine value. Wijs method is commonly used for determining iodine value. The greater the iodine value, the more unsaturation and higher the susceptibility to oxidation.

29. CONCLUSION 21-08-2024 Iodine value 29 Determination of iodine value is an important analytical method for fats and oils. Based on iodine value we can access whether the taila or ghrita is pure or adulterated. Iodine value also gives an idea about the shelf life and potency of taila and ghrita .

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31. 21-08-2024 Iodine value 31 THANK YOU